Automatic circuit breaker



NOV. 12, 1935. 1. SACHS 2,020,333

AUTOMATI C C IRCUIT BREKER Filed Oct. ll, 1953 3 Sheets-Sheet l azi//hc//ii 4 Inventar Nov. 12, 1935. J, SACHS 2,020,333

AUTOMATIC CIRCUIT BREAK/ER Filed Ooi. l1, 1933 3 Sheets-Sheet 2 Nov. l2, 1935. J. SACHS 2,020,333

AUTOMATIC CIRCUIT BREAKER Filed om. 11,1955 3 sheets-sheet 3 Inventar' I :fasi/Uh Eachs @mi mw tarngy Patented Nov. 12, 1935 UNITED STATES PATENT ol-ElcE f 42Clailns.

This invention relates particularly to an automatic circuit breaker of the type set forth in my Patents Nos. 1,811,970, 1,812,842, 1,812,843 and 1,812,846, all dated June 30, 1931.

One of the objects of the present invention is to provide an improved circuit breaker of the type referred to having the operating and actuating mechanism so constructed and arranged as to considerably reduce the stress or tension transmitted through the movable electro-responsive means. This is particularly important when the electro-responsive means is a bi-metallic thermostatic strip, as the reduction in the stress or tension in such a strip enables it to flex more freely and therefore to be more sensitive. With the reduced tension the strip can be of smaller cross sectional area than would otherwise be necessary. This general object of the invention is attained by means of a nov'el mechanical arrangement of parts which is such that a portion of the stress is transmitted from the actuator or actuating member directly to the contact member entirely independently of the thermostatic strip or other electro-responsive means.

Another object of the invention is to provide in a circuit breaker of the type referred to an arrangement of parts which enables the operating handle to serve as a means for indicating that the circuit breaker has operated automatically. This result is attained by so constructing and arranging the parts that upon automatic operation the handle, instead of automatically moving to its full open-circuit position, moves only part way and stops at an intermediate indicating position.

In my copending application entitled Automatic circuit breaker, Serial No. 691,139, filed September 27, 1933, I have disclosed a construction wherein the two movable contacts are positioned between the outer planes of the main insulating elements or side plates of the movable contact member, thus making it possible for the circuit breaker as a whole to be much narrower than was possible with the earlier constructions. Another object of the present invention is to provide an arrangement of parts which makes it possible for the circuit breaker to be even narrower than that disclosed in thesald application. In eilecting this object of the invention I make use of the invention disclosed in the said copending application,

that is, I locate the movable contacts between the outer planes of the side plates of the contact member, but, instead of arranging the contacts side by side in transverse alignment, I arrange them in tandem. thus making it possible for the two side plates to be much closer together and for the entire circuit breaker to be correspondingly narrower.

A further object of the invention is to provide certain advantageous details of construction and 5 connection of the thermostatic strip. which details are particularly useful when the movable contacts are arranged in tandem. 'I'his present object of the invention will be more fully apparent from the following specification.

A still further object of the present invention is to provide a circuit breaker so constructed that it is possible for the automatic action thereof to be considerably delayed under ordinary moderate over-load conditions without, however, interfering with the rapid automatic action in the case of an excessive over-load or short-circuit. A related and more specilic object of the invention is to provide a means of adjustment which makes it possible to change the degrees of delay or the rates of operation under excessive and moderate over-load conditions.

A still further object of the invention is to provide for a circuit breaker of the type described a means for adjusting the sensitivity of the thermostatic bi-metallic strip or latch. In accordance with this phase of the invention it is possible for the sensitivity of the strip to be adjusted to meet diflerent operative conditions or to compensate for minor variations or inaccuracies in manufacture.

Another object of the invention is to provide improved venting means for permitting arcformed gases to be discharged under proper control and guidance.

Still other objects of the invention will be apparent from the following specification and claims.

In the accompanying drawings I have shown one principal embodiment of the invention and a variety of alternative details. It will be understood that the drawings are intended to be for illustrativeI purposes only and are not to be construed as dening or limiting the scope of the invention, the claims forming a part of this speciiication being relied upon for that purpose.

Of the drawings:

Fig. 1 is a front view of a circuit breaker embodying the invention.

Fig. 2 is a view similar to Fig. 1, but showing the front insulating cover removed.

Fig. 3 is a longitudinal sectional view taken along the line 3--3 of Fig. 2 and showing the movable parts in their closed-circuit positions.

Fig. 4 is a transverse sectional view taken 55 along the line 4-4 of Fig. 3, but omitting the front cover.

Fig. 5 is a detail perspective view showing an insulating block constituting a part of the insulating enclosing structure.

Fig. 6 is a fragmentary view similar to Fig. 4, but showing an alternative construction.

Fig. 7 is a longitudinal sectional view taken along the line 'I-l of Fig. 2 and showing the movable parts in their open-circuit positions.

Fig. 8 is a fragmentary view similar to Fig. 7, but showing the movable parts in the positions which they occupy at the beginning of the automatic circuit-opening operation.

Fig. 9 is a fragmentary view similar to Figs. 7 and 8, but showing the movable parts in different relative positions.

Fig. 10. is a detail sectional view taken along the line ID-IIJ of Fig. .7.

Fig. ,11 is a detail perspective view showing certain parts of the contact member separated from eachother. Y

Figs. 12 to 16 are detail views similar to the central part of Fig. 11 and showing alternative constructions which may be used in lieu of that shown in Fig. 11.

Fig. 17 is a fragmentary view similar to Figs. 8 and 9, but showing an alternative construction, the movable parts being in their closed-circuit positions.

Fig. 18 is a detail perspective view of the thermostatic latch and associated parts shown in Fig. 17.

Fig. 19 is a view similar to Fig. 18, but showing an alternative construction. A

A circuit breaker of the type set forth in my beforementioned Patents Nos. 1,811,970, 1,812,842 and 1,812,843 includes a movable contact member provided with a movable contact adapted to engage and disengage a stationary contact, and also includes a movable actuating means or actuator which normally serves to eect the movement of the contact member to bring the movable contact into or out of engagement with the stationary contact. An electro-responsive means is provided on the contact member which normally engages the actuating means or actuator and serves to releasably connect the said contact member with the actuator. Upon the attainment of abnormal current conditions in the circuit-the electro-responsive means disengages the actuator to permit the contact member to automatically move independently to its opencircuit position. 'I'he electro-responsive means is preferably a lai-metallic thermostatic strip which normally serves in and of itself as a releasable latch normally connecting the contact member with the actuator and which is adapted upon deiection from its normal relationship to disengage the actuator and thus permit the described independent movement of the contact member.

In my before-mentioned Patent No. 1,812,846 there is shown a construction wherein the means which normally eiects the movement of the contact member is connected directly therewith so as to substantially reduce the force which must be transmitted to the movable contact member by means of the electro-responsive means such as the bi-metallic strip. In accordance with the present invention I utilize the principle disclosed in my said Patent No. 1,812,846 but the said principle is differently embodied in that there is provided an actuating means or actuator which has direct engagement with a bodily movable part ofthe contact member and which is releasably engaged by the thermostatic strip so that upon the attainment of vabnormal current conditions the actuator is free to move relatively to the contact member and entirely in- 5 dependently of the thermostatic strip. In view of the fact that the actuator is directly engaged with the contact member only a portion of the force required for moving and holding the contact member is transmitted to the said member 10 through the strip.

'Ihe contact member and the actuating means or actuator may .be variously constructed and related within the scope of the invention, and as concerns the present phase of the invention I do 15 not necessarily limit myself to particular details. However, I will now describe an embodiment of the invention wherein the contact member is pivotally movable and wherein the actuating member is pivotally mounted on the contact mem- 20 ber for relative movement about an eccentric axis. This particular construction has many definite advantages as will presently appear, but it will be understood that the invention in its broader aspects is not limited to any particular 25 types of movement or to any speciilc details of construction.

Referring to the drawings, I represents the main insulating base or support which carries all of the other parts of the circuit breaker. 30 Fitting the support I at the front thereof is an insulating cover 2. The rear support I is of boxlike form, being substantially closed at all four sides and at the bottom. The front cover is also of more or less box-like form, having a recess 35 open at the bottom into which certain parts of the mechanism project. When the two parts I and 2 are assembled as shown, there is provided an interior recess which contains all of the operative parts of the circuit breaker other than the 40 handle.

Carried by the rear support I near the front thereof are two forward projecting parallel metallic plates 3, 3 which are held in place by means of screws I, I extending forward from 45 the rear of the support. The plates 3, 3 are provided with integral rearward extending portions 3", 3l. Carried by the said rearward extensions 3*, 3* and extending transversely between them is a pivot pin s. Pivotnuy mounted on the pin 50 5 is a contact carrying member which includes two parallel plates 8, 6 spaced apart transversely and suitably connected together to move as a unit. These plates have aligned bearing apertures through which the pivot pin 5 extends, 55 shoulders on the pin serving to hold the plates in proper spaced relationship. Suitable spacing washers, not shown, hold the plates in prcper spaced relationship to the supporting plate extensions as, v. 60

The two plates 6, l serve to carry the main movable contacts of the circuit breaker, and while I do not necessarily so limit myself, I prefer. in pursuance of one oi' the objects of the invention, to construct and arrange the contacts in a 05 manner to be now described. 'I'he two contacts 1 and 8 are positioned between the outer planes of the two insulating side plates, as set forth in my said copendlng application Serial No. 691,139; but instead of being arranged side by 70 side in transverse register with each other, as shown in the said application, they are arranged in tandem, that is, they are spaced apart in the direction of movement, that is, circumferentially. Preferably and as will be clearly apparent from 75 an examination of Figs. 10 and 11, each movable contact 1 and 8 extends from one to the other of the two plates 6, 6 and is in direct engagement with both of them. Preferably and as shown each of the said plates 6 is provided with a hole 3 and a notch III adapted to receive-similarly shaped lateral projections on the corresponding contact. When the said projections on the contacts are entered in the said holes and notches of the two plates, the contacts are iirmly held in proper predetermined relationship.

It will be observed that, by reason of the tandem arrangement of the contacts, the two plates 6, 6 are much closer together than would otherwise be possible. The movable contacts are not only coniined between the outer planes of the movable plates as disclosed in my aforesaid application. but by reason of the tandem arrangement I am enabled to have each contact extend the entire distance from one of the said plates to the other, thus insuring ample contact width and at the same time attaining a very consider- .able reduction in the distance between the two plates. The reduction in the distance between the plates makes it possible for the entire circuit breaker to be correspondingly narrower.

'I'he two plates 6, 6 are additionally connected and held in spaced relation by means of insulating members II and I2. 'i'he said members II and I2 are preferably structurally separate from the plates, and as shown the plates are notched at I3, I4, I5 and I5 to receive projections I1, I8, I3 and 28 formed on the insulating members. members are held in proper relationship by means of tie rods or rivets 2l, 2I extending through suitable holes 22, 22 and 23, 23. Preferably the plates 6, 6 have arcuate outer edges concentric with the pivotal axis at 5 and the insulating members II and I2 are externally shaped to conform to these arcuate edges. It will be apparent that the insulating members II and I2 extend transversely from plate to plate and that the movable contact 1 extends through the space between the two members. The member II engages with the other movable contact 8 and thus extends circumferentially from one contact to the other.

The two movable contacts 1 and 8 are electrically connected with each other, this electrical connection preferably being through an electro-responsive means which is carried by and is bodily movable with the contact member. By preference and as shown. this electro-responsive means is a bi-metallic thermostatic strip 24 mechanically and electrically connected directly with one of the contacts, as for instance the contact 1. The strip 24 is provided at its projecting end with a lug 25 which enables the strip to serve as a latch as will be presently explained.

In order to complete the electrical connection between the two contacts 1 and 8 there is provided a suitable flexing or flexible connection 26 between the strip 24 and the contact 8. This flexing connection may be widely varied as to details, as will be presently explained, but as shown in Figs. 3, 7, 8, 9 and 1l it consists of a series of thin laminations formed of copper or other suitable metal. These laminations are riveted drectly to the strip 24 and to the contact 8 as shown. 'Ihe strip 26 is suiiiciently dexible to permit the bi-metallic strip 24 to freely deflect or bend under the influence of heat.

Carried by the insulating support I are two 'Ihe two plates and the insulatingsubstantially stationary main contacts 21 and 28 which are connected with the said support by means of more or less resIlicntbent conducting straps 28 and' 38. These stationary contacts 21 and 28 are so positioned and arranged that they .5 can be iirmly engaged respectively by the two movable contacts 1 and 8 as clearly shown in Fig. 3. 'I'he outer end of the supporting strap 28 engagesthebottomwalloi a recess 3l inthe support I and the said strip is held in place by 10 means of two screws 32 which also hold a conductor 33. This conductor projects from the circuit breaker at the right and may be connected at 33n directly with the bus bar of a panel board `or may be provided with a suitable wire engaging l5 terminal. 'Ihe outer end of the conducting strap 30 engages the bottoln wall of'a recess 34 formed in the main support I and is held in place by screws 35 which also hold a laterally extending conductor 36. The conductor 36 is provided with 20 a wire terminal 36*V and suitable recesses 31 are formed in the upper left hand corners of the support I and of the cover 2 to permit access to the said wire terminal.

From the f dcrlption it will be ap- 25 parent that pivotal t of the contact member serves to bring the movable contacts 1 and 8 into or out of engagement with the respective stationary contacts 21 and 28 to make or break the circuit. When the parts are in the 30 contact engaging position as shown in Fig. 3 electrical connection is established between the conductor or terminal 33 and the terminal 36. A suitable spring means is provided for biasing the member in the contact g or circuitopening direction. As shown there are two separate springs 38, 38 mrrounding the pin 5 and positioned between the supporting plate extensions 3, 3* and the insulating plates 6, 6.

For actuating the contact member for normal 40 switching purposes or to effect closing of the circuit after automatic opening thereof, I provide a member which I shall term an actuating member or actuator. This member is normally engaged by the thermostatic strip or latch 24, and 45 in accordance with the present invention the actuator is so positioned and connected that a portion of the areas of actuation is transmitted directly from the Yactuator tothe contact member'independently of the thermostatic latch. The 50 actuator is shown at 33, and preferably it is pivoted to the contact member for movement about a bodily movable axis. When the contact member is pivotally movable, as is preferred and as is shown, the actuating member is mounted for 55 movement about an eccentric axis. As illustrated and as preferred, the'actuating member 39 is ofv bell crank form and consists of two spaced metallic plates pivotally mounted on a pin 48 extending transversely between the two 60 side plates 6, 6. A transverse pin 4I serves to limit relative movement of the actuating member in the counter-clockwise direction. The actuating member is provided with a transverse pin or roller 42 which.' at normal temperatures, is 65 engaged by the lug 2l on the thermostatic latch 24. With the parts in the relative positions shown in Fig. 3, the actuator and the contact member are positively connected to move in unison.

For manually operating the actuator 39 I pro- 70 vide a handle member 43 which is mounted on a pin 44 extending ly between the supporting plates 3, 3. The handle member projects through an in the front wall of the front cover 2, the mening being of suilicient 75 spring 4l which serves to bias the handle toward its open-circuit position, that is, in the counterclockwise direction from the pomtion shown in Fig. 3. The handle member 43 is connected with the actuator 39 by means of two similar links 46, 45, the links being pivoted to the handle member at 41 and to the actuator at 43.

When the parts are in the relative positions shown in Fig. 3 thelinks 44 cooperate with the handle member 43 to form a toggle which locks the parts in position with the movable contacts 'l and 3 pressed into ilrm engagement with the stationary contacts 21 and 23. Continued movement of the handle in the clockwise direction is prevented by the engagement of an extension 43l thereon with a pin 43 extending transversely between the plates 3, 3. The pivotal axis at 4I is above a straight line connecting the pivotal axes at 44 and 48, and thus the handle member 43 and the links 46 serve to resist the tendency of the contact member to move in the clockwise direction under the influence of the springs 38, 38 and of the resilient contact supporting strips 29 and 30. At the same time the said toggle action holds the handle 43 in its right hand or closed-circuit position, resisting the tendency oi the spring 45 to move the handle member in the counter-clockwise direction.

The above-described toggle action can be released by pressing the handle toward the lei't, the parts then moving under the action o! the springs 38 and 45 to the open-circuit positions shown in Fig. 7. 'I'he movable contacts 1 and 8 are thus disengaged from the stationary contacts 21 and :aand the circuit is broken in two separate places. By moving the handle toward the right the several parts can be restored to their respective positions, as shown in Fig. 3, and the circuit can be thus re-established.

It will be evident that the force required tor moving and holding the coniact member is transmitted through the links 46 to the actuator 38 and from the actuator to the contact member. The normal connection between the actuator and the contact member is partly through the pivot pin at 40 and partly through the thermostatic latch 24. By reason of the fact that the actuator 39 engages directly with the contact member through the pivot pin 40, the stress transmitted through the latch 24 is much less than it otherwise would be. It will be evident that the stress transmitted through the links 46 is in the direction of the line :c-x appearing on Fig. 3, the said stress acting on the actuator at a distance a from the pivotal axis thereof. The tendency is to relatively rotate the actuator in the clock- Wise direction, but such rotation is resisted by the thermostatic latch 24 acting at a distance b from the pivotal axis 40. Inasmuch as the distance a is considerably less than the distance b only a fraction of the pressure exerted by the links 46 is transmitted to the latch 24. Obviously by changing the proportions of the parts the relationship between the dimensions a and b can be varied in any desired manner.

As already explained the bi-metallic strip 24 is electrically connected between the movable contacts l and 8. It is adapted to be deilected downward or outward upon the passage oi excess current therethrough, with the result that the lug 25 is disengaged from the pin or roller 42, such disengagement being shown in Fig. 8. This disengagement or partial disengagement permits length to permit the necessary movmentsot the handle. [s shown in Fig. 4 there is provided a the actuator 3l to turn slightly relatively to the contact member and in the clockwise direction. This slight clockwise movement reduces the pressure whichhad theretoiore served to hold the links 44 and the handle member 43 in their 5 etlective toggle relationship. This reduction in pressure permits the handle member 43 to move in the counter-clockwise direction so as to render the toggle inei'lective. By reference to Fig.

8 it will be observed that the pivotal axis at 41 10 has moved below the dot-and-dash line connecting the pivotal axes at 44 and 4I, thus freeing both the contact member and the handle member so that they are automatically moved to their open-circuit positions under the iniluence of the springs 3l and 4l. It will be understood that the contact member and the handle member move substantially simultaneously, the lug 25 and the pin or roller 42 perhaps never becoming completely disengaged from each other. When the parts reach their full open-circuit position, as shown in Fig. 7, the lug and the pin or roller 42 can freely re-engage as soon as the thermostatic strip 24 has suillciently cooled.

The relationship between the actuator and the 25 bi-metallic strip is dlierent in detail from that shown and described in my said Patent No. 1,812,846. In the present construction the actuator is at least partially disengaged from the bimetallic strip upon the attainment of excess current conditions and may be entirely disengaged therefrom it the handle be held as shown in Fig. 9. This is in contrast with the construction shown in the said patent wherein the member to which the toggle links are connected is permanently connected with the bi-metallic strip and is relatively movable only to the extent o! the deilection of the strip.

It will be observed that the contact member together with the actuator and the bi-metallic thermostatic latch carried by the said contact member constitute a movable self-contained unit. 'I'he movement of this sell-contained unit is guided and controlled by the bearing at B, but inasmuch as the actuator is carried directly by the side plates of the contact member any possible inaccuracy or looseness at the bearing 5 will in no way ail'ect the accuracy or the operating characteristics of the circuit breaker. As already explained, the actuator 39 is pivoted to 50 the contact member at 40 between the side plates 6. 8, and the actuator and the bi-metallic latch 24 normally remain in ilxed relationship with each other and with the contact member, there being no relative movement at the bearing 40 55 except upon automatic opening or the circuit breaker and even then the movement is very slight. A considerable amount oi' relative motion occurs at the bearing 5 and this relative motion occurs every time the device is operated either manually or automatically to open or close the circuit; but even if there should be a considerable amount oi looseness or relative play at the bearing 5, whether resulting from wear or otherwise, such looseness or play cannot ailfect the accuracy or operating characteristics oi' the circuit breaker, which as already explained are dependent solely upon the relationship between the latch 24 and the actuator 39.

It will be further observed that the latch 24 70 projects or extends from its point of attachment substantially in the direction of contact disengaging or circuit-opening movement, this arrangement being in distinct contrast to what is disclosed in my betorementioned patents. This reversed position of the latch, together with the peculiar construction and mounting of the actuator, are important factors in obtaining the advantageous results that have been described.

The described circuit-opening movement of the contact member is not in any way dependent on the circuit-opening movement of the handle member and will, in fact, occur cven though the handle 4member be held in its closed-circuit position, as shown. by full lines in Fig. 9. The downward or outward deflection of the thermostatic strip 24 permits the actuator 33 to turn in the clockwise direction as already stated, thus releasing the contact member from the control of the handle member 43 and of the links 43. The contact member moves in the clockwise direction to the position shown in Fig. 9, the actuator 33 and the links 43 assuming the relative posi-y tions shown by full lines in that gure. If the handle 43, after having been held as described, be now released, it will move under the inuence of the spring 45 to its open-circuit position as shown in Fig. '7, thus bringing the actuator 39 into its normal position with respect to the contact member so that the pin or roller 42 can be engaged by the lug 25.

Under some conditions it may be preferable to utilize the handle 43 as a means for conveniently indicating that the circuit breaker has operated automatically. When this is desired the handle 43, instead of being biased toward its closed-circuit position, may be biased toward an intermediate indicating position, as shown by dotted lines in Fig. 9. Y This result may be accomplished by providing two oppositely acting springs 53 and 5 i, as shown in Fig. 6. When the handle member is thus biased to an intermediate indicating positionthe circuit-opening action is the same as already described, with the single exception that the handle member 43, instead of moving to its open-circuit position, moves to the hintermediate indicating position as shown by dotted lines in Fig. 9, the links 43 and the actuator 33 taking corresponding positions as shown by dotted lines in the same figure. 'Ihe intermediate position of `the handle 43 will indicate to an observer that the circuit breaker has been opened automatically and not manually, because if manually opened the handle would be in the open-circuit position as shown in Fig. 7. This gives opportunity to investigate the circuit conditions to determine the -cause of the automatic opening. When it is desired to close the circuit breaker it is necessary to first move the handle 43 to the full open-circuit position in order to eiect re-engagement of the lug 25 with the pin or roller 42. After that the circuit breaker can be closed in the usual manner as before described.

It may under some circumstances be desirable to regulate the action of the strip 24 in order to vary the operating characteristics of the circuit breaker and in order to compensate for initial variations or inaccuracies of manufacture. In order that this result may be accomplished I provide means on the contact member adapted to apply transverse pressure to the strip. This means may be widely varied Vas to details, but as shown there is a member 32 extending transversely between the two plates 3, 3, its ends being seated in apertures 53 in the said plates. Extending through the transverse member 52 is a screw 54 adapted to engage directly with the thermostatic strip 24 to apply transverse pressure thereto. It will be apparent that the screw 54 when brought into pressure contact with the strip assists the deecting action thereof and thus causes the strip to deflect and disensage the actuator more quickly under the influence of a smaller overload.

In lieu of the laminated flexible conductor 23 5 which has been described, any one of several different less exible, but nevertheless flexing. conductors may be used. It may be preferable vto use a second bi-metallic thermostatic strip as the flexing conductor, such a strip being shown l0 at 55 in Fig. 12. This strip is shown as being rigidly connected by riveting or otherwise to the strip 24 and to the movable contact 3.

In Fig. 13 I have shown an alternative construction wherein the main strip 33 is bifurcated l5 and wherein the connecting strip 31 is formed integrally with the main strip, being in fact the central portion of the said strip bent away from the main plane thereof so as to be connected directly to the movable contact 3. The strip 51 is 20 shown as being welded to the contact 3.

In Fig. 14 I have shown a construction which is similar to that shown in Fig. 13, the difference b eing that the construction is reversed, there being a main central bi-metallic strip 53 and two 25 connecting strips 33 formed integrally at the sides of the main strip and bent downward away from the plane thereof so as to be connected with the movable contact 3.

In Fig. l5 I have shown a rigid intermediate 30 conductor 33 connected to the movable contact 3. The main thermostatic strip is shown at 3| and this is formed with an integral extension 32 which is connected directly with the rigid intermediate conductor 33. 35y

In Fig. 16 I have shown a strip 33 which is oppositely slotted longitudinally at 34 and 35 to provide an intermediate portion 33 and an auxiliary longitudinal portion 31. 'I'his auxiliary longitudinal portion 31 is directly connected with 40 the movable contact 3 as shown.'

It will be apparent that with any of the constructions shown in Figs. l2 to 16 the action of the bi-metallic exing connecting conductor is such as to cooperate with and augment the act5 tion of the main thermostatic strip or latch. In each instance the main strip and the auxiliary strips cooperate to move the lug 25 downward or outward out of engagement with the pin or roller 42 on the actuator 33.' 50

In Figs. 1'7 and 18 I have shown alternative details oi' construction for effecting the latching engagement between the actuator and the thermostatic strip. I have shown a one-piece actuator 33 in lieu of the two-piece actuator 33, it be- 55 ing understood that the one-piece actuator 33 is located between the two links 43, 43 and held in place by spacing bushings. The actuator 33, instead of having a pin or roller such as 42, is provided with a relatively sharp edge or corner as 60 shown at 33. The thermostatic strip 33 is provided with an aperture 13 therein corresponding in function to the lug 25, the portion 33* of the actuator normally entering the aperture. As the result of this construction, the position of disen- 55 gagement is more sharply determined than is the case with the lug and roller construction shown in the other figures.

The construction shown in Figs. 17 and 18 makes it possible to provide any reasonable predetermined delay or time lag in the automatic operation of the circuit breaker when the current is not greatly in excess of the predetermined capacity, without however seriously interfering with the prompt operation of the circuit breaker under short circuit conditions. 'Ihis result is obtained by confining the direct heating action or" the current to a portion thereof immediately adjacent the rigidly supported end, leaving the free end of the strip to be heated solely by heat transmitted or conducted from the current-carrying portion adjacent the supported end. I have shown a flexible connector 1I electrically connected with the movable Contact I and electrically connected with the strip il at a point substantially spaced from the latching aperture 10 therein. 'I'he flexible connector 1I is shown as consisting of two stranded flexible wires, but as to this I do not limit myself. The connecting of the flexible connector at the position shown confines the direct heating action to the inner portion of the strip between the contact 1 and the connector 1I. y

If there is a moderate overload when the circuit is first closed, that is, with the thermostatic strip initially cold, the inner portion of the strip becomes heated and slightly deected upon the occurrence of a moderate overload, but the outer part of the strip is not initially affected, as it carries no current, and it remains substantially straight. With only a moderate overload the ilexure of the inner portion of the strip does not cause sufficient movement of the apertured end of the strip to disengage it from the actuator 68 and the circuit breaker remains closed. notwithstanding the moderate excess current flowing therethrough. However, if this excess current is continued, heat is slowly transmitted from the inner portion oi the strip I9 so as to heat the outer portion thereof, and after a short interval the said outer portion is bent or deilected, with the result that the aperture 10 is withdrawn far enough to become disengaged from the actuator 8l. 'I'his permits the circuit breaker to open as already described. If the moderate overload occurs after the thermostatic strip has reached its normal running temperature and has therefore become slightly deiiected, the additional deflection necessary to effect release will occur more quickly; but the additional deflection will neverthele be somewhat delayed because the direct heating takes place only in one end portion. a

It will be apparent that, within reasonable limits, any desired or predetermined time interval of overload operation can be provided by properly determining the position of connection of the iiexible conductor to cause the current to flow through a requisite portion of the length of the strip. 1

Notwithstanding the delayed action which is obtained in the event of only a moderate excess current, the action of the circuit breaker is reasonably prompt in the event of an extreme excess current or a short-circuit, particularly if the short circuit occurs after the strip has reached its normal running temperature. In the event of such extreme excess current or short circuit, the direct heating action, as already stated, is confined to the inner portion of the strip 89, but this heated portion is at a considerable distance from the latching end of the strip having the aperture 10 therein; and the result is that they said latching end is moved quickly downward and outward without waiting for the outer portion of the strip to become exed as the result of transmitted heat.

In order that the amount of delay or time lag may be varied or regulated to meet different conditions, it may be desirable to provide an adjustment so that the position of engagement of the exible connecting conductor may be changed. In Fig. 19 I have shown the main thermostatic strip 12 as having a series of holes 1l, 13, and

I have shown the flexible connector 1I connected s during initial assembly, and in such case it may 15 be preferable to omit all holes except the one actually needed.

I have only briey described the supporting and enclosing members I and 2, as these may be widely varied according to the use to which the 20 circuit breaker is to be put. As shown these parts are so formed and related as to partcularly adapt the circuit breaker for panel board use; but, it will be understood that the invention is by no means so limited. I have heretofore re- 25 ferred to a recess II in which are located parts of the conductors 29 and 33. Preferably in order that this recess may be normally substantially closed I provide an extension or lug 1B on the cover 2 which projects rearward into the said 30 recess. I have also referred to a recess 34 in which are located portions of the conductors 30 and 36. In order that this recess may normally be substantially closed I preferably provide a separate insulating block 16 adapted to ilt this recess. 35 Preferably the sides of the recess 34 are provided with grooves 11, 11 and the block 16 is provided with tongues 1l, 18 adapted to enter the said grooves and thus hold the block 16 in place.

In order that the two members I and 2 may be 40 permanentlyl connected together so as to prevent unauthorized tampering with the mechanism of the circuit breaker, I preferably provide tubes 19,

19 which extend through suitable holes in the two members I and 2, the tubes being flanged as 45 shown at 80, 80 in Figs. 1, 3 and 7. It will be apparent that when the tubes 19, 19 have been put in place and flanged over the two members I and `2 are permanently connected together. In order to secure the circuit breaker to the panel board or 50 other supporting structure, screws may be extended through the said tubes 19, 19.

'Ihe cover member 2 is preferably relatively thick and is provided with two separate finger recesses Il, BI to permit convenient access to the 55 handle 4l. These spaced finger recesses make it very diillcult for the handle to be moved slowly, and practically insure quick handle movements which eil'ect quick making and breaking of the circuit. 60

Preferably the front cover member 2 is provided with threaded inserts 82, 82 which may be used to receive screws extending through the dead front plate of the panel board.

For controlling and confining the arc-formed 65 gases I provide means similar to those disclosed in my copending applications entitled Automatic circuit breakers, Serial Nos. 690,584 and 690,585, both nled September.. 22, 1933. The path of movement of each movable contact is surrounded by four insulating walls, three of the walls being stationary and one of the walls being movable. For the cont-act 1 the movable wall is the outer surface 83 of the insulating member I2 and for the contact 8 the movablev wall is the outer surface 75 wall 84.

84 of the insulating member Il. The main support I is formed with an arcuate wall .l concentric with the said wall and the auxiliary block 16 is formed with -a wall 8l concentric with the Discharge vents l1 extend downward from the surface and communicate with a duct 88, which duct is closed at the rear by means of a separate insulating plate I. 'held by the before-mentioned connecting-Juices 1l, 19. The duct 88 communicates with afduct 90 which terminates in a discharge opening at the left hand end oi the circuit breaker' and in the recess 31. Formed in the block 10 are vents Il, ll which communicate with a duct n in the block, this duct in turn communicating with an open notch 93 in the cover. It wlllbeapparent that, by means of the vents 81, 81 and Il, Il and the described ducts, the arc-formed gases can be discharged,

the construction being such that the gases are' cooled prior to discharge. What I claim is:

l. The combination in an automatic circuit breaker, oi' a stationary elechic contact, a movable contact member including an electric contact adapted to engage and dlsengage the stationary contact, the said membeal `being' biased in the contact disengasln direction, an electroresponsively controlled latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon the attainment of abnormal current conditions in the circuit, and actuating means for moving the contact member toward and holding it in the contact engaging position, the said actuating means having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid and the said means also having movable engagement directly with the contact member so that the force transmitted through the latch is less than the total force required for moving and holding the contact member.

2. The combination in an automatic circuit breaker, of a. stationary electric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, a bi-metalllc thermostatic current-carrying strip on the contact member electrically connected with the movable contact and adapted to be deflected from its normal relationship to the said member upon the attainment in the strip of an abnormal current condition, and actuating means for moving the contact member toward and holding it in the contact engaging position, the said actuating means having an engagement with the strip adapted to be released upon deflection oi the latter as aforesaid and the said means also having pivotal engagement directly with the contact member so that a portieri of the force required for moving and holding'the contact member is transmitted directly to the said member independently of the strip.

3. An automatic circuit breaker comprising in combination, 'a stationary electric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, means for supporting and guiding the contact member, an electro-responsively controlled latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon the attainment ot abnormal current conditions in the circuit. an actuator supported upon the contact member entirely independently of the said supporting and guiding means for the said member and normally having an engagement with the latch adapted to be -released 5 upon automatic movement oi' the latter as aforesaid, and means for operating the said actuator to enable it to normally etlect movement of the contact member to and from its contact engaging position. l0 4. An automatic circuit breaker comprising in combination, two stationary electric contacts, a movable contact member including two electric contacts adapted to engage and disengage the respective stationary contacts, the said member 15 A entirely independently of the said supporting and guiding means for the said member and normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for oper- 30 ating the said actuator to enable it to normally eil'ect the movement of the contact member to and from its contact engaging position.

5. An automatic circuit breaker comprising in combination, a stationary velectric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, means for l supporting and guiding the contact member, an 40 electro-responsively controlled latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon the attainment of abnormal current conditions in the circuit, an actuator supported upon the contact member entirely independently of the supporting and guiding means for the said member, the said actuator being bodily movable with the contact member and normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for operating the said actuator to enable it to normally eiect movement of the contact member to and from its contact engaging position.

6. An automatic circuit breaker comprising in combination, a stationary electric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, means for biasing the member in the contact disengaglng direction, an actuator bodily movable with the contact member and also movable relatively thereto about an axis transverse to the direction of bodily movement, and an electro-responsively controlled means on the contact member normally engaging the actuator to prevent relative pivotal movement thereof, the said means upon the attainment of abnormal current conditions in the circuit releasing the actuator to permit rlative pivotal movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

7. An automatic circuit breaker comprising in combination, a stationary electric contact, a

'movable contact member including an electric 75 contact adapted to engage and disengage the stationary contact, means for biasing the member in the contact disengaging direction, an actuator bodily movable with the contact member and also movable relatively thereto about an axis transverse to the direction of bodily .movement, and a bl-metallic thermostatic strip on the contact member normally engaging the actuator to prevent relative pivotal movement thereof, the said strip being subject to deflection upon the attainment of abnormal current conditions in the circuit and the said strip when so deflected disengaging the actuator to permit relative pivotal movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

8. An automatic circuit breaker comprising in combination, two stationary electric contacts, a movable contact member including two transversely spaced insulating side plates and also including two separate electric contacts carried by the side plates adapted to respectively engage and disengage the stationary contacts, the said side plates having bearing surfaces whereby the contact member is guided for movement in a substantially fixed path, a bi-metallic thermostatic current-carrying latch on the contact member and electrically connected between the two movable contacts, the said latch being adapted to be automatically moved from its normal relationship to the said contact member upon the attainment of abnormal current conditions in the circuit, an actuator positioned between the two side plates and pivotally supported thereon entrely independently of the said bearing surfaces thereof, the said actuator normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforesaid, and means for operating the said actuator to enable it to normally effect movement of the contact member to and from its contact engaging position.

9. An automatic circuit breaker comprising in combination, a stationary electric contact, a pivotallyr movable contact member including an electric contact adapted to engage and disengage the stationary contact, means for biasing the member in the contact disengaging direction, an actuator carried by and bodily movable with the contact member and also pivotally movable relatively thereto about an eccentric axis, and an electro-responsively controlled latch on the contact member normally engaging the actuator to prevent relative pivotal movement thereof, the said latch upon the attainment of abnormal current conditions in the circuit disengaging the actuator to permit relative pivotal movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

l0. For use as a part of an automatic circuit breaker, a movable unit comprising a .contact member having an electric contact adapted to engage and disengage a stationary contact, the said member having a bearing surface byrmeans of which it may be guided for movement in a substantially xed path, an electro-responsively controlled latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon the attainment of abnormal current conditions in the cir-` cuit, and an actuator supported upon the contact member entirely independently of the aforesaid bearing surface and normally having an engagement with the latch adapted to be released upon automatic movement of the latter as aforeaoadsas said, the said actuator being adapted for engagement with an operating means whereby the said contact member, latch and actuator may normally be moved as a unit.

ll. For use as a part of an automatic circuit breaker, a movable unit comprising a contact member having two electric contacts adapted to respectively engage and disengage two stationary contacts, the said member having a bearing surface by means of which it may be guided for 10 movement in a substantially fixed path, a bimetallic thermostatic current-carrying latch on the contact member adapted to be automatically moved from its normal relationship to the said member upon the attainment of abnormal current conditions in the circuit, and an actuator supported upon the contact member entirely independently of the aforesaid bearing surface and normally having an engagement with the latch adapted to be releasedV upon automatic move- 20 ment of the latter as aforesaid, the said actuator being adapted for engagement with an operating means whereby the said contact member, latch and actuator may normally be moved as a unit. 25

12. In an automatic circuit breaker, the combination of a stationary electric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased 30 in the contact disengaging direction, an actuator bodily movable with the contact member and also movable relatively thereto, and an electroresponsively controlled latch attached to the contact member and projecting from the point of attachment approximately in the contact disengaging direction, the said latch at its projecting end normally engaging the actuator to prevent relative movement thereof and the said latch upon the attainment of abnormal current conditions in the circuit disengaging the actuator to permit relative movement thereof and to thereby permit automatic contact disengaglng movement of the contact member.

13. In an automatic circuit breaker, the combination of a stationary electric contact, a movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, an actuator bodily movable with the contact member and also movable relatively thereto, and a bi-metallic thermostatic current-carrying strip on the contact member electrically connected with the movable contact and projecting therefrom approximately in the' contact disengaging direction, the said strip at its projecting end normally engaging the actuator to prevent relative movement thereof and the said strip upon deflection resulting from abnormal current conditions therein disengaging the actuator to permit relative movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

14. In an automatic circuit breaker, the combination of a stationary electric contact, a pivotally movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, an actuator carried by and bodily movable with the contact member and also movable relatively thereto, and a bi-metallic thermostatlc strip attached to the pivoted contact member projecting from the point of attachment approximately in the contact disengagingdirection, thesaid strip at its projecting end normally engaging the actuator to prevent relative movement thereof and the said strip upon deflection resulting from abnormal current conditions in the circuit disengaging the actuator to permit relative movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

15. In an automatic circuit breaker, the combination of a stationary electric contact, a plvotally movable contact member including an electric contact adapted to engage and disengage the stationary contact, the said member being biased in the contact disengaging direction, an actuator carried. by and bodily movable with the contact member and also pivotally movable relatively thereto about an eccentric axis, and a bi-metallic thermostatic current-carrying strip on the contact member electrically connected with the `movable contact and projecting therefrom approximately in the contact disengaging direction, the said strip at its projecting end normally engaging the actuator to prevent relative movement thereof and the said strip upon defiection resulting from abnormal current conditions therein disengaging the actuator to permit relative movement thereof and to thereby permit automatic contact disengaging movement of the contact member.

16. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction, a pivoted operating member, two pivotally connected links pivoted respectively to the operating and contact members and serving as an operative connection between them, an electro-responsively controlled means normally serving to prevent pivotal movement of one of the links relatively to the contact member and serving upon the attainment of abnormal current conditions in the circuit to permit such pivotal movement, and means for normally limiting relative movement of the other link and the operating member to enable the said link and member to serve 'as a releasable toggle normally holding the contact member in closedcircuit position.

17. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction, an actuating member pivoted to the contact member for movement about a movable axis but normally held against such relative movement, a movable operating member biased in the circuit-opening direction, a connecting means between the operating and actuating members adapted to move the actuating and contact members and also normally serving as a restraining means to hold all of the said members in their closed-circuit positions, and an electro-responsively controlled means normally serving to prevent pivotal movement of the actuating member relatively to the contact member, the said electro-responsive means serving upon the attainment of abnormal current conditions in the circuit to permit such pivotal movement of the actuating member and to thereby permit automatic circuit-opening movement of the contact member and the said means also serving to substantially simultaneously cause the release of the operating and actuating members from the restraint of the said restraining means and to thus permit them to automatically move from their closed-circuit positions.

18. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction, an actuating member pivoted to the contact member lfor relativo movement about a` movable axis but normally held against such relative movement, operating means including toggle links connected with the 5 actuating member and when in their effective positions serving to hold the said actuating and contact members in their closed-circuit positions. the said links being biased toward their ineective 'positions but being normally held in their eifec- 1o tive positions as the result of pressure resulting from the said bias of the contact member, and an electro-responsively controlled means normally serving to prevent the said pivotal movement of the actuating member and serving upon 15 the attainment of abnormal current conditionsin the circuit to permit such pivotal movement, the said pivotal movement of the actuating member serving to permit automatic circuit-opening movement of the contact member and also serv- 2o ing to simultaneously release the pressure on the toggle links and thus permit them to automatically move to their open-circuit positions.

19. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction, an actuating member pivoted to the contact member for relative movement about a movable axis but normally held against sch relative movement, operating means including toggle links connected with the actuating member and when in their eiective positions serving to hold the said actuating and contact members in their closed-circuit positions, the said links being biased toward their ineffective positions but being normally held in their effective positions as the result of pressure resulting from the said bias o.' the contact member, a bi-metallic thermostatic strip attached to the contact member and projecting from the point of attachment approximately in the circuit-opening 40 direction, the said strip at its projecting end normally engaging the actuating member to prevent the said pivotal movement thereof and the said strip upon deflection resulting from abnormal current conditions in the circuit disengaging the actuating member to permit such pivotal movement.

20. The combination in an automatic circuit breaker, of a movable contact member biased in the circuit-opening direction, an actuator normally movable in unison with the contact member,

a movable operating member biased to an intermediate indicating position between its open-circuit and closed-circuit positions, a connecting means between the operating member and the actuator adapted to move the actuator and the contact member and also normally serving as a restraining means to hold the said operating and contact members in their closed-circuit positions, and an electro-responsively controlled means nor- 6o mally serving to, prevent movement of the contact member relatively to the actuator, the said electroresponsive means serving upon the attainment of abnormal current conditions in the circuit to permit automatic independent circuit-opening moveg5 ment of the contact member and the said means also serving to substantially simultaneously cause the release of the operating member from the restraint of the said restraining means and to thus permit it to automatically move to its said intermediate indicating position.

21. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction, an actuator normally movable in unison with the contact mem- 76 links connected with the actuator and when in their effective positions serving to hold the said actuator and the contact member in their closed- 5 circuit positions, the said operating means being biased toward an intermediate'indicating position between its open-circuit and closed-circuit positions but being normally held with the toggle links in their effective positions as the result of pressure resulting from the said bias of the contact member, and an electro-responsively controlled means normally serving to prevent the said movement of the contact member relatively to the actuator and serving upon the attainment of abnormal l5 current conditions in the circuit to permit automatic circuit-opening movement of the contact member and also serving to simultaneously release the pressure on the toggle links and thus permit the operating means to automatically move to its said intermediate indicating position.

22. In combination in an automatic circuit breaker, a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, and a bi-metallic element electrically connected between the movable contacts and being rigidly connected at one end with one contact and being flexibly connected near the other end with the other contact, the said bi-metallic element serving in and of itself as a releasable latch nonnally movable with the actuator and the contact member and normally operative for mechanically connecting them to enable the former to eilect the movement of the latter to open or close the circuit and the said bi-metallic element being automatically deflected upon the passage of excess current therethrough to mechanically release the contact member from the control of the actuator and thus permit the said contact member to automatically move independently to its open-circuit position.

23. An automatic circuit breaker comprising in combination, a movable contact member biased in the circuit-opening direction and including two transversely spaced insulating side plates parallel to the direction of movement and also including two spaced electric contacts arranged in tandem between the outer planes oi' the side fplates, two stationary' electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, and an electro-responsively controlled means normally connecting the actuator and the contact member to prevent independent movement of the latter, the said means upon the attainment of abnormal current conditions in the circuit becoming ineffective and serving to permit automatic independent contact disengaging movement of the contact member.

24. An automatic circuit breaker comprising in combination, a movable contact member biased in 55 the circuit-opening direction and including two transversely spaced insulating side plates' parallel to the direction of movement and also including two spaced electric contacts arranged in tandem between the outer planes of the side plates, each 70 of the said contacts having oppositely projecting portions fitting holes in the respective plates, two stationary electric contacts engageable by the respective movable contacts, an actuator normally l movable in unison with the contact member, and 5 an electro-responsively controlled means normally sfoaoas ber, a movable operating means including toggle r connecting the actuator and the contact member to prevent independent movement of the latter, the said means upon the attainment of abnormal current conditions in the circuit becoming ineffective yand serving to permit auto- 5 matic independent contact disengaging movement of the contact member.

25. An automatic circuit breaker comprising in combination, a pivotally movable contact member biased in the circuit-opening direction and in- 1o cluding two transversely spaced insulating 'side plates perpendicular to the pivotal axis and also including two spaced electric contacts arranged in tandem between the outer planes of the side Y plates, an insulating barrier on the contact mem- 15 ber extending transversely from plate to plate and circumferentially from contact to contact, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, 20 and an electro-responsively controlled means normally connecting the actuator and the contact member to prevent independent movement of the latter, the said means upon the attainment of abnormal current conditions in the circuit 25 becoming ineffective and serving to permit automatic independent contact disengaging movement of the contact member.

26. An automatic circuit breaker comprising in combination, a movable contact member biased in 30 the circuit-opening direction and including two transversely spaced insulating side plates parallel to the direction of movement and also including two spaced electric contacts arranged in tandem between the outer planes of the side plates, two 85 stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, and a thermostatic bimetallic strip serving as a releasable latch normally mechanically connect- 40 ing the actuator and the contact member, the said latch being positioned between the two plates and being electrically connected between the two contacts so as to be automatically deflected upon the attainment of an abnormal current condi- 45 tion' and to thus release the contact member from the control of the actuator and permit the said contact member to automatically move independently to its open-circuit position.

27. The combination in an automatic circuit 50 breaker, of a movable contact member biased in the circuit-opening direction and including two spaced electric contacts, two stationary electric contacts engageable by the respective movable contacts, releasable mechanism normally holding 55 the contact member in closed-circuit position and including a thermostatic bi-metallic strip rigidly connected at one end with one movable contact and capable of deflection to cause the other end to relatively move and thereby effect the release of the mechanism, and a conductor electrically connecting the strip and thev other contact to complete the circuit through the strip and cause it to be automatically deflected upon the attainment of an abnormal current condition in the circuit, the last said conductor being structurally separate from the strip and being sumciently flexible to permit free deflection of the strip in accordance with the current condition therein.

28. The'combination in an automatic circuit breaker, of a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two stationary electric contacts engageable by the re- 16 contacts engageable by the respective movable spective movable contacts, releasable mechanism normally holding the contact member in closedcircuit position and including a thermostatic bimetallic strip rigidly connected at one end with one movable contact and capable of deflection to cause the other end to relatively move and thereby eilect the release of the mechanism, and a flexing conductor electrically connecting the strip and the other contact to complete' the circuit through the strip and cause it to be automatically deflected upon the attainment of an abnormal current condition in the circuit.

29. The combination in an automatic circuit breaker, of a movable-contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem,'two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, a thermostatic bi-metallic strip rigidly connected at one end with one movable contact and releasably engaging the actuator at the other end so as to normally serve as a connecting latch, and a flexing conductor electricaly connecting the strip and the other contact to complete the circuit through the strip and cause it to be automatically deflected upon the attainment of an abnormal current condition and tothus disengage the actuator and permit the said contact member to automatically move independently to its opencircuit position.

30. The combination in an automatic circuit breaker, of a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, a thermostatic bi-metallic strip rigidly connected at one end with one movable contact and releasably engaging the actuator at the other end so as to normally serve as a connecting latch, and a bi-metallic thermostatic conductor electrically connecting the strip and the other contact to complete the circuit through the strip, the said bi-metallic conductor cooperating with the strip to cause it to be automatically deflected upon the attainment of an abnormal current condition and to thus disengage the actuator and permit the said contact member toautomatically move independently to its open-circuit position.

3l. The combination in an automatic circuit breaker, of a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, and a thermostatic bi-metallic strip rigidly connected at one end with one movable contact and releasably engaging the actuator at the other end so as to normally serve as a connecting latch, the said strip having an integral portion bent from the main portion thereof and electrically connected with the other contact to complete the circuit through the strip and cause it to be automatically deflected upon the attainment of an abnormal current condition and to thus disengage the actuator and permit the said contact member to automatically move independently to its open-circuit position.

32. In an automatic circuit breaker, the combination of a movable contact member biased in the circuit-opening direction and including two spaced electric contacts, two stationary electric contacts, releasable mechanism normally holding the contact member in closed-circuit position and including a thermostatic bi-metallic strip rigidly connected at one end with one movable contact and capable of deflection to cause the other end to relatively move and thereby effect the release of the mechanism, and a conductor electrically connected with the other contact and with the strip at a pointsubstantially spaced from the relatively movable end thereof and serving to complete the circ'uit through a part of the strip so that said strip is automatically deflected rapidly upon the attainment of an excessive overload condition therein and is automatically deflected very slowly upon the attainment of a moderate overload condition therein, the last said conductor being structurally separate from the strip and being suillciently flexible to permit free deflection of the strip in accordance with the current condition therein.

33. In an automatic circuit breaker, the combination of a movable contact member biased in Y the circuit-opening direction and including two spaced electric contacts arranged in tandem, two a stationary electric contacts engageable by the respectivemovable contacts, releasable mechanism normally holding the contact member in closedcircuit position and including a thermostatic bimetallic strip rigidly connected at one end with Il one movable contact and capable of deflection to cause the other end to relatively move and thereby effect the release of the mechanism, and a exible conductor electrically connected with the other contact and with the strip at a point substantially spaced from the relatively movable end thereof and serving to complete the circuit through a part of the strip, whereby the said strip is automatically deflected rapidly upon the attainment of an excessive overload condition theremovable in unison with the contact member,l a f' thermostatic bi-metallic strip rigidly connected at one end with one movable contact and engaging the actuating member at the other end so as to serve as a connecting latch adapted to disengage the actuator upon electro-thermal deflection, i.

and a flexible conductor electrically connected with the other contact and with the strip at a point substantially spaced from the point of engagement with the actuator and serving to complete the circuit through a part of the strip, whereby the said strip is automatically deflected rapidly upon the attainment of an excessive overload condition therein and is automatically de- :Elected very slowly upon the attainment of a moderate overload condition therein.

35. In combination in an automatic circuit breaker, a contact biased for movement to break the circuit, releasable mechanism normally holding the contact in closed-circuit position and including a bi-metallic strip supported at Lone end and capable of deflection to cause the other end to relatively move and thereby effect the release of the mechanism, and means including a flexible conductor for connecting the bi-metallic strip into the circuit to enable it to be deflected upon the passage of excess current and thereby release the mechanism, the said ilexible conductor being connectible with the strip at different longitudinalLv spaced positions so as to change the rate of deflection thereof.

36. Inl combination in an automatic circuit breaker, a contact biased for movement to break the circuit, releasable mechanism normally holding the contact in closed-circuit position and including a bi-metallic strip bodily movable with the contact and electrically connected therewith at one end and capable ot deflection to cause the other end to relatively move and thereby etlect the .release of the mechanism, and a ilexible conductor for completing the circuit through the bimetallic strip to enable it to be deected and thereby release the mechanism upon the f of excess current, the said ilexible conductor being connectible with the strip at diii'erent longitudinally spaced positions so as to change the rate of deflection thereof.

37. In combination in an automatic circuit breaker, a movable contact member biased in the 'circuit-opening direction and including an elecmally movable in unison with the contactmember, a thermostatic bi-metallic strip rigidly connected at one end with the movable contact and engaging the actuator at the other end so as to serve as a connecting latch adapted to disengage the actuator upon electro-thermal deflection, a flexible conductor electrically connected with the strip at a point substantially spaced fromthe point of engagement with the actuator and serving to complete the circuit through a part of the strip, whereby the said strip is automatically deflected rapidly upon the attainment of an excessive overload condition therein and is automatically deected very slowly upon the attainment of a moderate overload condition therein, and means for changing the position o! the connection of the iiexible conductor to the strip to change the rates of deiiection under excessive and moderate overload conditions.

38. In combination in an automatic circuit breaker, a movable contact member biased in the circuit-opening direction and including two spaced electric contacts, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, a thermostatic bimetallic strip rigidly connected at one end with one movable contact and engaging the actuating member at the other end so as to serve as a connecting latch adapted to disengage the actuator upon electro-thermal deflection, a flexible conductor electrically connected with the other contact and with the strip at a point substantially spaced from the point of engagement with the actuator and serving to complete the circuit through a part of the strip, whereby the said strip is automatically deflected rapidly upon the attainment of an excessive overload condition therein and is automatically deflected very slowly upon the attainment of a moderate overload condition therein, and means for changing the position of the connection of the flexible conductor to the strip to change the rates of deilection under excessive and moderate overload conditions.

39. In combination in an automatic circuit breaker, a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two stationary electric contacts engageableby the at a point substantially spaced from the point o! 1o engagement with the actuator and serving to complete the circuit through a part of the strip. whereby the said strip is automatically deeceed rapidly upon the attainment of an excessive werload condition therein and is automatically dele ected very slowly upon the attainment of a moderate overload condition therein, and means for changing the position of the connection of the flexible conductor to the strip to change the rates oi' deilection under excessive and moderate 20 overload conditions.

40. The combination in an automatic circuit breaker, o1' a movable contact member biased in the circuit-opening direction and including two spaced electric contacts arranged in tandem, two 25 stationary electric contacts engageable by the respective movable contacts, an actuator normally movable in unison with the contact member, a thermostatic bi-metallic strip electrically connected between the movable contacts and en- :i0 gaging the actuating member at one end so as to serve as a connecting latch adapted to disengage the actuator upon electro-thermal deflection and to thus permit the said contact member to automatically move independently to its open-circuit i position, and means on the contact member adapted to engage the strip between its ends to regulate the deflection thereof.

41. The combination in an automatic circuit breaker, ot a movable contact member biased in 4.0 the circuit-opening direction and including two transversely spaced insulating side plates parallel to the direction ci! movement and also including two spaced electric contacts arranged in tandem between the outer planes of the side plates, two stationary electric contacts engageable by the respective movable contacts, an actuator normally movable -in unison with the contact member, a thermostatic bi-metallic strip positioned between the plates and electrically connected between the movable contacts and ensuring the actuator at one end so as to serve as a connecting latch adapted to disengage the actuator upon electro-thermal deflection and to thus permit the said contact member to automatically move independently to its open-circuit position, a cross bar extending between the two plates adjacent the strip, and an adjustable screw carried by the cross bar and engaging the strip to regulate the deflection thereof.

42. In an automatic circuit breaker, the combination of two stationary contacts, two movable electrically connected contacts adapted to engage and disengage the stationary contacts, the last said contacts being biased for movement in the 65.

circuit-opening direction and being normally held mechanically against such movement, an electro-responsive element arranged to be energized upon the attainment of an abnormal current condition in the circuit so as to mechanically release the said movable contacts and thus permit lthem to automatically move to open-circuit positions, and stationary insulating means including a main rear support and a separable block substantially completely enclosing the con- 7s tacts and including walls closely adjacent the ward therefrom and the said support and block path of movement of each movable contact, the respectively having two ducts communicating said main rear support and the said block respecwith the respective series of vents and each extiveiy having therein two separate series of vents tending to the exterior ot the insulating means. 5 each communicating with the arcing zone of the corresponding pair of contacts and extending out- JOSEPH SACHS.

ISCLAIMER 2,020,333.Joseph Sachs, West Hartford, Conn. AUTOMATIC CIRCUIT BREAKER. Patent dated November 12, 1935. Disclaimer led July 31, 1936, by the patentee. Hereb disclaims claim 35.

[ ical Gazette August 25, 1.936.]

[DISCLAIMER 2,020,333.-Joseph Sachs, West Hartford, Conn. AUTOMATIC CIRCUIT BREAKER. Patent dated November 12, 1935. Disclaimer filed July 31, 1936, by the patentee. A Hereb disclaims claim 35.

[ cial Gazette August Z5, 1.936.] 

